Cochlear Implant Reliability Data – An Independent Review

Recently the cochlear implant companies have stepped up their marketing around reliability.

Implant reliability is an important factor in deciding which company to go with. To replace an implant requires surgery and normally a minimum of a 3 week loss of function. In some cases it can take weeks to diagnose, 3 weeks for the scar to heal and then weeks or months for the new implant to stabilise and become as effective as the old one. In short it is much preferable that an implant lasts a life time rather than needing replacing.

However implants are electronic devices and their production is not perfect. Also they do get bumped about like every other part of the body. So a percentage will fault.

The implant companies provide data on failures. They report this in a variety of ways, even though there is an agreed way of reporting it. The International Consensus Group on Cochlear Implant Device Reliability Reporting have recommended a standard that is based on ISO standard 5841-2:2000. All manufacturers say they are adhering to it but there is debate around this both from a categorisation point of view and the supply of some information.

2ears2hear has acquired reliability information from the various manufacturer’s reports, websites and from direct information requests. This has been used to produce these three graphs. All three graphs have the same Y-axis which makes them easy to compare.

Advanced Bionics

The most current implant is the Hi-Res 90K (Post 2005) Supplier A. This is also the most reliable. Advanced Bionics has had some spectacularly bad implants. The Hi-Res 90K Supplier B (which is discontinued and no longer available) is approaching a failure rate of 40% after 8 years. However with the purchase of Advanced Bionics by Sonova, reliability of manufacture has been achieved.

Cochlear

Cochlear has had their own less spectacular failure with the CI500 series implant. This was recalled. It’s failure rate after five years is a bit over 7%. This is substantially less than Advanced Bionics.

Apart from the hiccup of the CI500 implant, Cochlear have shown consistent improvement in reliability as time has gone on – which is highly commendable.

Med-El

Med-EL has had no spectacular failures. They also have shown a good trend of improving reliability with each update to their implants – with one exception. The Concerto’s failure rate has popped slightly above the Sonata. Med-El now have the Concerto pin option which has returned the failure rate to below the Sonata.

General Comments and Observations

It is reasonable to expect each manufacturer to reduce their failure rate with each new implant design. This has happened with each manufacturer for the most part.

All manufacturers have highly reliable implants now. It would appear that the quality of manufacturing has been pushed close to the limits of perfection. Now the issues are around design and demographics of users.